Charged soot

Figure 1. Number concentrations of species in sooting acetylene/ oxygen flames as a function of height above the burner for different fuel equivalence ratios () and cM gas velocities (v). Pressure = 20 mm Hg points = experimental data curves = estimated trends, (a) Total soot particles (b) charged soot particles = 3.0, v= 50 cmisec, Wersborg (7) (c) targe positive ions = 3,0, v = 38 cm sec, Yeung (9) (d) and (e) total positive ions, different assumed species sizes (see text), = 3,5, v = 50 cmisec. Frier (S),...

Adams, D. E., Measurement Technique for Charged Soot Particles in... 

Figure 6. Comparison of present 0 = 3.0 Langmuir probe total ion concentration profile with other results. AeroChem, Langmuir probe HS, molecular beam Faraday cage ( ) (see text) neutral soot and charged soot (2l) > 1000 amu, neutral species (22).

The corrected ion and charged particle profiles in Figure 6, coupled with the information in Figure 1, could be looked at as a smooth progression from small ions to large molecular ions to large charged soot particles which produce neutral particles on recombination, consistent with an ionic mechanism of soot formation. 

The peak ion concentration in the well-studied c ) = 3.0 flame (2.7 kPa, 50 cm s ) has been established to be about 5 by two vastly different techniques in two laboratories, centration is comparable to the neutral and charged soot concentrations determined by a third technique in a third laboratory. Differences in spatial ion and charged particle concentration pro-... 

A classic definition of electrochemical ultracapacitors or supercapacitors summarizes them as devices, which store electrical energy via charge in the electrical double layer, mainly by electrostatic forces, without phase transformation in the electrode materials. Most commercially available capacitors consist of two high surface area carbon electrodes with graphitic or soot-like material as electrical conductivity enhancement additives. Chapter 1 of this volume contains seven papers with overview presentations, and development reports, as related to new carbon materials for this emerging segment of the energy market. 

The soot-free synthesis gas is then charged to a shift converter where the carbon monoxide reacts with steam to form additional hydrogen and carbon dioxide at the stoichiometric rate of 1 mole of hydrogen for every mole of carbon monoxide charged to the converter. 

Americium is a critical ingredient in smoke detectors. Some of the tiny particles released by an americium compound create a small electric charge inside smoke detectors. Smoke or soot can block the charge, which sets off the alarm. One gram of americium is enough for 5,000 smoke detectors. 

Selected results on number concentrations are presented on Figure 1. Wersborg s results were obtained at = 3.0 and o = 50 cm/sec. The soot particles (curve a) refer to particles larger than about 15 A diameter, measured by electron microscopy. The charged fraction of particles (curve b) was determined by measuring particle number with and without an electric field applied across the beam to remove all charged particles. Measurement error was estimated to be below 20%. 

Ionization by Charge Transfer. Many ion-molecule reactions between small species (< 50 amu) occur in flames (24), As mentioned above, the only primary ion in fuel-lean flames (non-sooting) is CHO", formed by chemi-ionization (13, 24, 25). 

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